Physical independence of force is a consequence of

Physical independence of force is a consequence of first law of motion.

The first law of motion, also known as the law of inertia, states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force. This law highlights the idea of physical independence of force because it implies that a force is only needed to change the state of motion (either to start, stop, or change the direction of motion) of an object. In other words, an object’s motion is independent of forces unless an external influence is applied.

• First law of motion establishes that forces do not alter the motion of objects unless an external influence is applied, meaning the object’s motion or rest is independent until a force is applied.
• The second law of motion (F = ma) defines how the velocity of an object changes when a force is applied, but it doesn’t address the independence of forces.
• The third law of motion states that for every action, there is an equal and opposite reaction, but this law pertains to interactions between forces and doesn’t specifically explain the physical independence of force.

Thus, the concept of physical independence of force is most directly tied to Newton's first law of motion.